asd.pl

	my $Indices = pdl(    #
		0, 3, 1,
		1, 3, 2,
		2, 3, 0,
		1, 2, 0,
	)->long;
	CreateVertexBuffer($Indices);
	

sub CalcNormals {
	my ( $pIndices, $IndexCount, $pVertices, $VertexCount ) = @_;

	# Accumulate each triangle normal into each of the triangle vertices
	for ( my $i = 0 ; $i < $IndexCount ; $i += 3 ) {
		my $Index0 = $pIndices->at( $i );
		my $Index1 = $pIndices->at( $i + 1 );
		my $Index2 = $pIndices->at( $i + 2 );
		my $v1     = $pVertices->slice( "($Index1),0:2" ) - $pVertices->slice( "($Index0),0:2" );
		my $v2     = $pVertices->slice( "($Index2),0:2" ) - $pVertices->slice( "($Index0),0:2" );
		my $Normal = $v1->crossp( $v2 );
		$Normal = $Normal->norm;

		$pVertices->slice( "5:7,($Index0)" ) += $Normal;
		$pVertices->slice( "5:7,($Index1)" ) += $Normal;
		$pVertices->slice( "5:7,($Index2)" ) += $Normal;
	}

	# Normalize all the vertex normals
	for my $i ( 0 .. $VertexCount - 1 ) {
		$pVertices->slice( "5:7,($i)" ) .= $pVertices->slice( "5:7,($i)" )->norm;
	}
}

sub CreateVertexBuffer {
	my ( $pIndices ) = @_;

	my $v = pdl(    #
		[ -1, -1, 0.5773,   0,   0, 0, 0, 0 ],
		[ 0,  -1, -1.15475, 0.5, 0, 0, 0, 0 ],
		[ 1,  -1, 0.5773,   1,   0, 0, 0, 0 ],
		[ 0,  1,  0,        0.5, 1, 0, 0, 0 ],
	)->float;

	my $type_size = howbig( $v->get_datatype );
	$self->VBO_vertex_size( $v->dim( 0 ) * $type_size );
	$self->VBO_tex_offset( 3 * $type_size );
	$self->VBO_normal_offset( 5 * $type_size );

	CalcNormals( $pIndices, $pIndices->nelem, $v, $v->dim( 1 ) );

	$self->VBO( glGenBuffersARB_p( 1 ) );
	glBindBufferARB( GL_ARRAY_BUFFER, $self->VBO );
	glBufferDataARB_s(
		GL_ARRAY_BUFFER,    #
		$v->nelem * $type_size,
		$v->get_dataref,
		GL_STATIC_DRAW,
	);

	return;
}